TSComputeIFunctionLinear#

Evaluate the left hand side via the user-provided Jacobian, for linear problems only

Synopsis#

#include "petscts.h"  
PetscErrorCode TSComputeIFunctionLinear(TS ts, PetscReal t, Vec U, Vec Udot, Vec F, void *ctx)

Collective

Input Parameters#

ts - time stepping context
t - time at which to evaluate
U - state at which to evaluate
Udot - time derivative of state vector
ctx - context

Output Parameter#

F - left hand side

Notes#

The assumption here is that the left hand side is of the form AUdot (and not AUdot + B*U). For other cases, the user is required to write their own TSComputeIFunction(). This function is intended to be passed to TSSetIFunction() to evaluate the left hand side for linear problems. The matrix (and optionally the evaluation context) should be passed to TSSetIJacobian().

Note that using this function is NOT equivalent to using TSComputeRHSFunctionLinear() since that solves Udot = A U